Shear blade thrust assister



Oct. 31, 1961 NlcOLETTA 3,006,072

SHEAR BLADE THRUST ASSISTER Filed March 17, 1959 2 Sheets-Sheet 1' Francesco Nicole/fa 1N VEN TOR.

BY QMw/EM WWW mg,

Oct. 31, 1961 F. NICOLETTA SHEAR BLADE THRUST ASSISTER 2 Sheets-Sheet 2 Filed March 17. 1959 Fig. 3

[\IIIIIIIIH Hill F rancesco Nicole/fa INVENTOR.

Q BY WW E United States Patent 3,006,072 BLADE THRUST ASSISTER "Francesco Nieoletta, San Anselmo, .Calif. (115 C ayton St, San Rafael, Calif.) Filed Mar. 17, 1959, Ser, 799,916 3 (CL .3.0..266)

invention relates to a new and useful shear blade thrust assister which may be constructed either as an attachment for shears, or as an integral thereof, being designed to .keep the shear blades in constant cutting contact thereby affording maximum cutting efliciencY at all times.

Many ,people using pru in shears have at one time or another tried to cut a limb or branch larger in diameter than that for which the shear we d g ed, with th result that the thrust applied to the shear blades caused them to spread apart so that the limb could not cut with lone .cutting motion. In such an instance several cutting actions are necessary resulting i .a .cut which not continuous or clean. It is a well known fact that this is not the preferred way to cut limbs or branches when pruning trees or shrubbery.

The vmain object of this invention is 10 proliide 1a idlev'ice which ay be incorporated into the manufacture of pruning shears and the like, or be attached to existing shears. The thrust assister will eliminate substantially all possibility of the shear blades not being in cutting contact with each other at all times.

A further object of this invention is to provide a shear blade thrust assister which will itself be adjustable in order to compensate for wear in either the pruning shears .or the thrust assister A still further object, inaccordance sevith the preceding objects, is to provide a shear blade thrust assister which may be attached to existing shears in a manner which Will not in any way interfere with the normal operation of the shears, and which will be of sturdy construction and lend itself to conventional forms of manufacture.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being bad to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a plan view of a conventional form of pruning shears shown with the arms of the shear blade assister comprising the present invention secured to the handles of the pruning shears, with the blades of the shears shown in the open position;

FIGURE 2 is a plan view, like that of FIGURE 1, but with the shears shown in the closed position and the arms of the thrust assister in overlying relation, parts of one arm being broken away and shown in section revealing the other arm disposed therebeneath;

FIGURE 3 is a transverse vertical sectional view taken substantially upon the plane indicated by the section line 3-3 of FIGURE 2;

FIGURE 4 is a longitudinal vertical sectional view taken substantially upon the plane indicated by the section line 4-4 of FIGURE 1;

FIGURE 5 is a plan view of the right arm of the shear blade assister as seen in FIGURE 1;

FIGURE 6 is a side elevational view of the right arm of the shear blade assister as seen in FIGURE 5;

FIGURE 7 is a vertical longitudinal sectional view taken substantially upon the plane indicated by the section line 7--7 of FIGURE 5;

FIGURE 8 is an enlarged plan view of the left arm of the shear blade assister as seen in FIGURE 1; and

FIGURE 9 is a side elevational view of the left arm of the shear blade assister as seen in FIGURE 8.

3,ll06,072 Patented Oct. 31, 1961 2 Referring now more specifically 10 the the numer l .10 genera ly designates the hear bl de thrust ass ster comprising the presentnventio se FIGURE 2,. .niounted upon a con entional if nn of pruning s ars 12 having two blade elements 14, a .piyot bolt 16 and two hand po ions .18-

' lhe shear b ade thrust ass st r .10 comp ises a first arm .20. attached in any sunr n en m nner 1.0 on of the handle portion 18 and a second sun 22. First 2.0 is in the form of an el nga ed strap, ha g e d secured to one of the handles 18 of the shears 12, and e tends lat al y mereit m towar s the other h ndle .Second am 2215 also inthe formof a e on ted str p having ione end sec r d .to handl 18 of the sh s 12 w th the oth r e d projecting la erally ther nrom toward the other h ndle 18, s e I URE 1. Eormed .on the secu ed .end .of ,22, at .theside edges, are first flanges .124, see .HGURE 4, which exte d at sigh ang r ir m terminating in ou ume ng s v 6 ereby prOY ing a pocket 28 between the secured \end of the second arm 22 and the .corresponding handle 18.. The second zzis-securedto handle 18in any onv ni nt manner by means or the second flanges 26. 7

A s en in FIGURE 1 of the n w ngs, even when th pruning shears 12 are in he open posi n, h confr n n ends-cfthe .20 .and..2.2 are in overlying con c i ml-afiollwhim fil handl PQMQ S 1,8 are moved ,tonether .to cl se the blade e ements v14, arm 20 d 2.2 -sjI ide towards .each other in .oyerlapping relation as the pruning shears .12 are moved to the completely closed p sition, ee FIGURE The slid -F2 tact betwe n the arms .20 and 2.2 assures that the blade elemen s .1 due t .a ex ess of thrust .caused by .a large or tough fsh tanch being cuttherebetw en. are not rce out o cutting contact with each other.

It will be further noted from a comparison of FIG- URES 1 and 2 that as the blades close, the area of contact of the overlapping arms 20 and 22 progressively increases thereby proportionately increasing the reinforcing of the blades against lateral distortion as they progress in their cutting action.

As can thus be seen by FIGURE 2 of the drawings, the free end of the first arm 20 is received within the pocket 28 of the secured end of the second arm 22 as the blade elements 14 are moved to the closed position.

As shown in the drawings, see FIGURES 1 through 4, the preferred method of securing the arms 20 and 22 to their respective handle portions 18, is by forming a. pair of bores 30 through each of the secured ends of arms 20 and 22 in alignment with apertures 32 formed in the corresponding handles 18, and by passing and securing through the aligned bores 30 and apertures 32 threaded machine screws 34 by means of lock washers 36 and nuts 38'.

If desired, the remote ends of bores 30 and apertures 32 may be provided with beveled counterbores 40 and enlarged portions 42 respectively so as to receive countersunk screws 34 and the nuts 38 therefor in flush relation, see FIGURES 3 and 4.

To enable the shears 12 to be used in more confined spaces, the surface of the free end of arm 22 which is remote from the free end of arm 20 is outwardly beveled as at 44, see FIGURES 3 and 6, so as to provide a reduced end portion which will be less likely to restrict the shears 12 from being used in confined areas. Further, to provide greater strength for arm 20, a bevel shoulder portion 46 is provided thereon which terminates in abutting relation to the inside edge of the handle 18 to which it is secured.

It is to be understood that both of the arms 20 and 22 are constructed ofa rigid material which will allow them to overcome considerable thrust which may be placed upon the pivot bolt 16 while the shears are being used to cut either branches which may be of greater diameter than for which the shears were intended, or smaller branches of extremely hard wood.

Further, it is to be understood that although not shown,

shims may be provided for insertion between arm 20 and handle 18 to which it is secured to compensate for v any wear of the contacting surfaces of arms 20 and 22. Thus it can be seen that herein described is' a device which will, while increasing the cutting power of pruning shears, also add to the length of time such shears may be used before being rendered inefiective because of excess amounts of thrust being placed upon the cutvention as claimed.

What is claimed as new is as follows:

1. For use with a pair of shears having a pair of pivotally connected shear blades each with a handle portion on the opposite side of the pivot, a thrust assister com prising a pair of generally flat, elongated arms each having one end secured to one of said handle portions with the free end thereof extending laterally therefrom towards the other arm, said arms being disposed in sliding contacting overlapping engagement and in the same relation to each other as are the corresponding blades, one of said arms having on its secured end a pair of parallel laterally extending and laterally offset flanges which are parallel to said last mentioned arm by which the latter is secured to the corresponding handle portion 4 forming a pocket between said last mentioned arm and the corresponding handle portion which is adapted to receive the free end of the other arm when said blades are pivoted to the closed position.

2. The combination of claim 1 wherein both of said arms are secured to the same side of corresponding handle portions and the underlying arm is removably secured to its corresponding handle portion whereby a shim may be placed between the underlying arm and the handle portion to which it is secured to efiect a greater pressure of one arm bearing against the other.

' 3. For use with a pair of shears having a pair of piyotally connected shear blades each with a handle portion on the opposite side of the pivot, a thrust assister comprising a pair of generally flat, elongated arms each having one end secured to one of said handle portions with the free end thereof extending laterally therefrom towards the other arm, said arms being disposed in sliding contacting overlapping engagement and in the same relation to each other as are the corresponding blades,

one of said arms having on its secured end a pair of ceive the free end of -the other arm when said blades are pivoted to the closed position, and the other arm has a shoulder portion thereon engaging in abutting relation the inner surface of the handle portion to which it is secured.

References Cited in the file of this patent UNITED STATES PATENTS 903,370 Frey Nov. 10, 1908 2,348,90 1 Hart May 16, 1944 

